Pregnancy and Pulmonary Hypertension

Pregnancy causes many changes in the body, all of which put enormous strain on a body already living with pulmonary hypertension (PH).

Doctors recommend that people with PH avoid getting pregnant due to the dangers to the mother and baby. In fact, studies show that between 3 to 5 out of every 10 women with PH die during pregnancy. The most common reasons for death are heart failure and arrhythmias. If you have PH and become pregnant, your doctor will likely talk to you about terminating your pregnancy.^1-3

However, not all people with PH know they have the disease. One study found 1 out of every 4 people with PH linked to congenital heart disease (CHD) and 16 percent of those with pulmonary arterial hypertension (PAH) are diagnosed for the first time during pregnancy. PAH is the most common type of PH diagnosed in women.²

Potential complications of PH during pregnancy

Pulmonary hypertension is risky for both the mother and the baby. For the pregnant person, the risks include:¹

• Many of the drugs used to control PH are toxic to the baby. Stopping these drugs can make PH worse.
• The heart and lungs are already under strain if someone has PH. Pregnancy and delivery add to that strain because body fluid and blood volume increase. More fluid increases pulmonary artery pressure because the heart must push more blood with every beat.
• Higher blood volume stresses the heart and can cause heart failure, especially in the right ventricle because the heart is unable to handle the heavier workload.
• Pregnancy increases the risk of blood clots. If a blood clot lodges in your lungs, it can cause a pulmonary embolism, which will worsen your PH.
• Pregnancy may lower blood oxygen levels, which may mean mother and baby need supplemental oxygen.
• Normal blood loss and the anesthesia and pain drugs given during delivery may cause blood pressure to fall, and that can lead to heart failure and death.

The risk is equally high for babies with preterm birth, low birth weight, and lower survival rate all being common.¹

Advice for pregnant people with PH

Your doctors will aim to keep your pulmonary hypertension under tight control if you become pregnant since this will help improve your outcome, as well as the outcome for your baby. Pregnant people with PH should see a team of experts experienced in managing high-risk pregnancies in people with heart disease. This team should include at least a cardiologist and anesthesiologist.⁴

Things your doctors may recommend to keep you as healthy as possible during pregnancy include:⁴

• Exercise as much as possible, within limits
• Bed rest, especially during the third trimester
• Wear compression socks while walking
• Take iron and folic acid to reduce the risk of anemia
• Get flu, pneumonia, and COVID vaccines to boost immunity

People with PH should see their healthcare team every 2 weeks during the first 20 weeks of pregnancy and every week past 20 weeks. These exams should include a regular obstetric exam plus tests for heart function, blood oxygen levels, and overall health.⁴

The baby also needs an ultrasound at every exam to track their growth. Poor growth is common in babies born to people with PH. The mother may need to go into the hospital for additional treatment if the baby’s condition becomes severe.⁴

Yes, pregnancy is dangerous for people with PH. However, some studies show outcomes are improving for those with well-controlled pulmonary hypertension.²